Needle-shaped heating element and aerosol-forming device

ABSTRACT

A needle-shaped heating element includes: an electrically conductive outer tube; and a heating circuit and a temperature measurement circuit arranged in the outer tube. One electrode of the heating circuit and one electrode of the temperature measurement circuit are both electrically connected to the outer tube. In an embodiment, the heating circuit includes a metal positive temperature coefficient (PTC) material.

CROSS-REFERENCE TO PRIOR APPLICATION

This application is a continuation of International Patent Application No. PCT/CN2020/134299, filed on Dec. 7, 2020. The entire disclosure is hereby incorporated by reference herein.

FIELD

The present invention relates to the field of vaporization, and more specifically, to a needle-shaped heating element and an aerosol-forming device.

BACKGROUND

Heat not burn e-cigarette, or referred to as low-temperature baking cigarette device, is an aerosol-forming device that heats tobacco or other aerosol-forming substrates in a low-temperature heat not burn way to form an inhalable aerosol. Mainly a heating element is used to precisely control the temperature and heat the tobacco after being energized, to rapidly release tobacco extracts in the tobacco under low-temperature conditions.

An existing needle-shaped heating element generally includes a heating circuit for generating heat to heat the aerosol-forming substrate after being energized and a temperature measurement circuit for measuring the temperature. The heating element generally includes multiple electrode leads, leading to the problem that a large number of electrode leads are required or the distance between electrode leads is small.

SUMMARY

In an embodiment, the present invention provides a needle-shaped heating element, comprising: an electrically conductive outer tube; and a heating circuit and a temperature measurement circuit arranged in the outer tube, wherein one electrode of the heating circuit and one electrode of the temperature measurement circuit are both electrically connected to the outer tube.

BRIEF DESCRIPTION OF THE DRAWINGS

Subject matter of the present disclosure will be described in even greater detail below based on the exemplary figures. All features described and/or illustrated herein can be used alone or combined in different combinations. The features and advantages of various embodiments will become apparent by reading the following detailed description with reference to the attached drawings, which illustrate the following:

FIG. 1 is a schematic three-dimensional structural diagram of a heating element according to some embodiments of the present invention;

FIG. 2 is a schematic cross-sectional structural view of the heating element shown in FIG. 1 ;

FIG. 3 is a schematic exploded structural view of the heating element shown in FIG. 1 ; and

FIG. 4 is a schematic three-dimensional structural diagram of an aerosol-forming device according to some embodiments of the present invention.

DETAILED DESCRIPTION

In an embodiment, the present invention provides a needle-shaped heating element requiring a small number of electrode leads and an aerosol-forming device having the needle-shaped heating element, to solve the above-mentioned defects of the prior art.

In an embodiment, the present invention provides a needle-shaped heating element, including an electrically conductive outer tube and a heating circuit and a temperature measurement circuit arranged in the outer tube, where one electrode of the heating circuit and one electrode of the temperature measurement circuit are both electrically connected to the outer tube.

In some embodiments, the heating circuit is made of a metal positive temperature coefficient (PTC) material.

In some embodiments, the temperature coefficient of resistance of the heating circuit is 1500-3500 ppm.

In some embodiments, the temperature measurement circuit is made of a metal PTC material, or the temperature measurement circuit adopts a thermocouple structure.

In some embodiments, the heating element further includes a first electrode lead electrically connected to the outer tube.

In some embodiments, the first electrode lead is welded to the outer side of the bottom of the outer tube.

In some embodiments, the heating element further includes a needle embedded in the top of the outer tube.

In some embodiments, the one electrode of the heating circuit and the one electrode of the temperature measurement circuit are both press-fit between the needle and the outer tube, to electrically connect to the outer tube.

In some embodiments, the needle includes a columnar insertion portion embedded in the outer tube and a conical guide portion connected above the insertion portion.

In some embodiments, the heating element further includes an insulating rod arranged in the outer tube, and the heating circuit and the temperature measurement circuit are wound outside the insulating rod.

In some embodiments, the heating circuit is arranged on the outer layer of the temperature measurement circuit.

In some embodiments, an insulating layer is formed between the heating circuit and the temperature measurement circuit by dipping or spraying.

In some embodiments, the heating element further includes a second electrode lead electrically connected to the other electrode of the heating circuit and a third electrode lead electrically connected to the other electrode of the temperature measurement circuit.

In some embodiments, the material of the outer tube is a high-temperature-resistant alloy or metal material.

In some embodiments, the outer tube is filled therein with a high-temperature-resistant insulating medium, and is coated thereon with a ceramic coating.

In some embodiments, the heating element further includes a base, and the lower end of the outer tube is inserted on the base.

In some embodiments, the base is made of a ceramic material.

In some embodiments, the lower end of the outer tube is welded to the base through a ceramic paint.

The present invention also provides an aerosol-forming device, including the heating element according to any one of the above embodiments.

Beneficial Effects

Implementation of the present invention at least has the following beneficial effects: One electrode of the heating circuit and the temperature measurement circuit are both connected to the outer tube, and the heating circuit and the temperature measurement circuit share one electrode, thereby reducing the number of electrode leads required in the heating element.

In order to have a clear understanding of the technical features, objects and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in FIG. 1 -FIG. 3 , a needle-shaped heating element 1 in some embodiments of the present invention may include an electrically conductive outer tube 11, a needle 12 embedded in the top of the outer tube 11, an insulating rod 14 longitudinally arranged in the outer tube 11, a heating circuit 15 and a temperature measurement circuit that are arranged in the outer tube 11 and one electrode of which is electrically connected to the outer tube 11, a first electrode lead 17 electrically connected to the outer tube 11, a second electrode lead 18 electrically connected to the other electrode of the heating circuit 15, a third electrode lead 19 electrically connected to the other electrode of the temperature measurement circuit, and a base 13 arranged at the bottom of the outer tube 11. One electrode of the heating circuit 15 and one electrode of the temperature measurement circuit are electrically connected to the outer tube 11, and therefore are electrically connected to the first electrode lead 17. The heating circuit 15 and the temperature measurement circuit share one electrode, thereby reducing the number of electrode leads in the heating element. In addition, the first electrode lead 17 is led out from the outer tube 11, which can increase the distance between the electrode leads.

The insulating rod 14 may be made of a high-temperature-resistant insulating material, for example, a high-temperature-resistant insulating ceramic material, may be substantially in the shape of a long cylinder and may include a first segment 141, a second segment 142, and a third segment 143 connected sequentially from top to bottom. The diameter of the second segment 142 is greater than the diameters of the first segment 141 and the third segment 143, and less than the inner diameter of the outer tube 11. The first segment 141 may be tightly embedded in the needle 12 and thus fixed. A step surface formed between the first segment 141 and the second segment 142 may abut against the bottom surface of the needle 12. The third segment 143 may be tightly embedded in the base 13 and thus fixed.

The heating circuit 15 and the temperature measurement circuit may be spirally wound outside the second segment 142 along the axial direction. The heating circuit 15 is configured to generate heat to heat an aerosol-forming substrate after being energized, and may be made of a metal positive temperature coefficient (PTC) material. The resistance of this material tends to increase with the increase of temperature. According to user requirements, the temperature coefficient of resistance of the heating circuit 15 may be 1500-3500 ppm. The temperature measurement circuit may be made of a metal PTC material, or may also adopt a thermocouple structure.

The heating circuit 15 and the temperature measurement circuit may adopt an interlayer structure. To be specific, the temperature measurement circuit is located in the inner layer, and the heating circuit 15 is located in the outer layer. During preparation, the temperature measurement circuit is first wound and fixed to the insulating rod 14, and the insulating layer is formed by dipping or spraying. After sintering and curing, the heating circuit 15 is then wound. Finally, the insulating rod 14 is fixed by the needle 12 at the top and the base 13 at the bottom. The second electrode lead 18 welded to the lower end of the heating circuit 15 and the third electrode lead 19 welded to the lower end of the temperature measurement circuit are led out along with the insulating rod 14.

The needle 12 may be made of a high-temperature-resistant alloy or metal material, such as stainless steel. In some embodiments, the needle 12 may include a guide portion 121 on the upper part and an insertion portion 122 on the lower part. The guide portion 121 is conical, to facilitate insertion into the aerosol-forming substrate. The diameter of the large end of the guide portion 121 is equal to the outer diameter of the outer tube 11 and greater than the outer diameter of the insertion portion 122. The insert portion 122 is cylindrical and is tightly embedded in the outer tube 11, and the step surface formed between the guide portion 121 and the insert portion 122 tightly presses against the upper end surface of the outer tube 11. The upper ends of the heating circuit 15 and the temperature measurement circuit are press-fit to the outer tube 11 through the guide portion 121 of the needle 12, to electrically connect to the outer tube 11, and therefore electrically connect to the first electrode lead 17. The first electrode lead 17 is welded to the outer side of the bottom of the outer tube 11 to electrically connect to the outer tube 11.

The outer tube 11 is tubular, and may be made of a high-temperature-resistant alloy or metal material, such as stainless steel. The outer tube 11 is filled therein with a high-temperature-resistant insulating medium, and is coated thereon with a ceramic coating. The base 13 may be a ceramic structural member, and may be welded to the outer tube 11 through a ceramic paint. The top surface of the base 13 is recessed to form a mounting groove 130, the outer tube 11 is embedded in the mounting groove 130, and the bottom surface of the outer tube 11 may abut against the bottom surface of the mounting groove 130. The bottom surface of the base 13 is recessed to form electrode holes 131 in communication with the mounting groove 130. At least three electrode holes 131 are provided respectively for the first electrode lead 17, the second electrode lead 18, and the third electrode lead 19 to pass through.

As shown in FIG. 4 , the aerosol-forming device in some embodiments of the present invention may be substantially in the shape of a square column and include a housing 2, a heating element 1 arranged in the housing 2, and a battery arranged in the housing 2 and electrically connected to the heating element 1. An aerosol-forming substrate 3 may be inserted into the housing 2 from the top of the housing 2. The upper end of the heating element 1 is inserted into the aerosol-forming substrate 3. After being energized to generate heat, the heating element 1 heats and bakes the aerosol-forming substrate 3 to form an aerosol for the user to inhale. It may be understood that the aerosol-forming device is not limited to the shape of a square column, and may alternatively be in the shape of a cylinder and other shapes.

The first electrode lead 17 of the heating element 1 may be electrically connected to the positive electrode of the battery, and the second electrode lead 18 and the third electrode lead 19 of the heating element 1 may be electrically connected to the negative electrode of the battery. Alternatively, the first electrode lead 17 of the heating element 1 may be electrically connected to the negative electrode of the battery, and the second electrode lead 18 and the third electrode lead 19 of the heating element 1 may be electrically connected to the positive electrode of the battery.

It may be understood that the foregoing technical features may be used in any combination without any limitation.

The foregoing embodiments only describe preferred embodiments of the present invention, and the description is specific and detailed, but cannot therefore be understood as a limitation to the patent scope of the present invention. It should be noted that, for a person of ordinary skill in the art, the foregoing technical features may be combined freely, and several transformations and improvements without departing from the conception of the present invention, all of which fall within the scope of protection of the present invention. Therefore, any equivalent transformations and modifications made to the scope of the claims of the present invention shall fall within the scope of the claims of the present invention.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.

The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C. 

What is claimed is:
 1. A needle-shaped heating element, comprising: an electrically conductive outer tube; and a heating circuit and a temperature measurement circuit arranged in the outer tube, wherein one electrode of the heating circuit and one electrode of the temperature measurement circuit are both electrically connected to the outer tube.
 2. The heating element of claim 1, wherein the heating circuit comprises a metal positive temperature coefficient (PTC) material.
 3. The heating element of claim 2, wherein a temperature coefficient of resistance of the heating circuit is 1500-3500 ppm.
 4. The heating element of claim 1, wherein the temperature measurement circuit comprises a metal positive temperature coefficient (PTC) material, or the temperature measurement circuit comprises a thermocouple structure.
 5. The heating element of claim 1, further comprising: a first electrode lead electrically connected to the outer tube.
 6. The heating element of claim 5, wherein the first electrode lead is welded to an outer side of a bottom of the outer tube.
 7. The heating element of claim 1, further comprising: a needle embedded in a top of the outer tube.
 8. The heating element of claim 7, wherein the one electrode of the heating circuit and the one electrode of the temperature measurement circuit are both press-fit between the needle and the outer tube so as to electrically connect to the outer tube.
 9. The heating element of claim 7, wherein the needle comprises a columnar insertion portion embedded in the outer tube and a conical guide portion connected above the insertion portion.
 10. The heating element of claim 1, further comprising: an insulating rod arranged in the outer tube, wherein the heating circuit and the temperature measurement circuit are wound outside the insulating rod.
 11. The heating element of claim 10, wherein the heating circuit is arranged on an outer layer of the temperature measurement circuit.
 12. The heating element of claim 11, wherein an insulating layer is formed between the heating circuit and the temperature measurement circuit by dipping or spraying.
 13. The heating element of claim 1, further comprising: a second electrode lead electrically connected to an other electrode of the heating circuit and; a third electrode lead electrically connected to an other electrode of the temperature measurement circuit.
 14. The heating element of claim 1, wherein the material of the outer tube is a high-temperature-resistant alloy or metal material.
 15. The heating element of claim 1, wherein the outer tube is filled with a high-temperature-resistant insulating medium and is coated with a ceramic coating.
 16. The heating element of claim 1, further comprising: a base, wherein a lower end of the outer tube is inserted on the base.
 17. The heating element of claim 16, wherein the base comprises a ceramic material.
 18. The heating element of claim 16, wherein the lower end of the outer tube is welded to the base through a ceramic paint.
 19. An aerosol-forming device, comprising: the heating element of claim
 1. 